DON'T FLUSH: Research shows that chemicals from prescriptions dumped into the sewage system could find their way into our drinking water. (Photo: Carly & Art/Flickr)

Despite what you’ve seen in the movies, you usually shouldn’t flush your drugs down the toilet. The EPA issued new guidelines yesterday that suggest putting expired prescriptions in sealed containers with kitty litter or coffee grounds to prevent drug abuse and harm to the environment.

"Following these new guidelines will protect our nation's waterways and keep pharmaceuticals out of the hands of potential abusers,” says EPA administrator Stephen Johnson in an article in the Washington Post.

When people empty unused or expired prescriptions into their toilets, the drugs often end up in lakes and rivers. Scientists have found more than 100 chemical compounds in water samples taken from both surface and groundwater in the United States and Europe. Research shows that chemicals from prescriptions dumped into the sewage system could find their way into our drinking water.

Frighteningly, scientists also admit that they aren’t sure how the combination of chemicals in the water could affect humans, let alone plants and animals. So far, one researcher found that “this mixture of drugs at environmental levels inhibited the growth of human embryonic kidney cells,” according to the journal Environmental Science and Technology.

Another study published in Environmental Toxicology and Chemistry found that hormones from drugs in waste water can make male tadpoles female. “Our findings show that frogs are more sensitive to hormone-disrupting environmental pollutants than we previously thought,” Cecilia Berg, the researcher of the study, said in a press release.

The EPA recommendations state that “drugs should be flushed down the toilet only if the label says it's safe to do so,” and if people follow these directions, well that’s a start. But when it comes to non-flushable drugs, we have to wonder how many people are actually going to take the time to package their old prescriptions with the grounds from this morning’s coffee or the litter from their kitty’s box.

Story by Susan Cosier. This article originally appeared in Plenty in February 2007. This story was added to MNN.com in July 2009.